<?

$a=array(
  'section1' => array (
    'sub11' => 'value',
    'sub12' => 'bbb1',
    'sub13' => 'bbb2',
  ),
  'section2' => array (
    'sub21' => 'value',
    'sub22' => 'bbb1',
    'sub23' => array(
		  'sub1' => array (
		    'subs1' => 'ss1',
		    'subs2' => 'ss2',
		    'subs3' => 'ss3',
		  ),
		),
  ),
);
$b=array(
  'section2' => array (
    'sub21' => 'NEW VALUE',
    'sub23' => array(
		  'sub1' => array (
		    'subs3' => 'NEW VALUE',
		  ),
		),
  ),
);

//5.3.0
if(phpversion()>'5.3.0') $c=array_replace_recursive($a, $b);
else $c=array_merge_recursive($a, $b);

echo '<pre>',print_r( $c, true),'</pre>';

?>
